Nadia Swanson lost her entire family the same day – her mother to a heart ailment, and her two little “sisters” to red tape.

Only six hours after her mother, Angela Bolton, died April 1, officials came to her door and took away the two youngsters, Bolton’s foster kids.

At just 20, Nadia is eager to take on the responsibility for their care. But 20 is too young, according to city and state rules.

“It was horrible to see someone so close to you go off with a stranger,” Nadia said from her mother’s empty home in Brooklyn’s Crown Heights. “It was just horrible. I begged them to let me take them.

“I know the children would prefer staying here. They’d prefer being in the same environment than go anywhere else.”

Bolton took in the girls, Ida and Raquel, just days after they were born.

Ida’s birth mother is incarcerated and relinquished all rights to the girl, who turns 8 next week.

Raquel, 4, was born to parents who are mentally disabled.

“This is the best place for them,” Swanson said of the only home the kids have known.

Lakeside Family and Children’s Services – a non-profit agency working with the city’s Administration for Children’s Services – won’t allow Swanson to become their guardian because she’s 11 months shy of her 21st birthday.

“They were part of the family, and it was a close family,” said Joyce Carter, Lakeside’s vice president.

“The two kids do consider [Nadia] to be their older sister.”

But rules are rules, she firmly stated, and the kids have been sent to another foster home.

“Foster parents must be at least 21 years of age,” she said. “We explained this to her and recognize the importance of her staying in contact with the girls.

“We have afforded her contact. We didn’t sever their ties,” Carter said. “But she can’t be a foster parent … It’s the law.”

Swanson, a nursing student who works part-time at a mental health care agency, is fighting for her family.

She was told she can apply for an exemption from the age requirement and has requested a hearing.

Swanson said if she gets the kids, she’ll juggle her schedule “like any other single mother” so she’s home when the girls are home. She points out she meets all the requirements for a foster parent – a steady income, adequate housing and no criminal record.

“Right now, I’m going through turmoil,” Swanson said. “I feel that no one can take care of my siblings the way I can.

“I can continue what my mom was doing and raise them the same way with love, care and academics too. I can provide what my mom did because I learned from her.

“Eleven months shouldn’t make a difference,” she said.

Carter said once she turns 21 she can petition to take the girls – but that doesn’t guarantee she’ll get them, since they may be with another family by then.

Swanson, though, doesn’t see why the girls’ lives should be disrupted again.

“It’s unfair to have the children go through so many transitions,” she said. “The best thing would be for them to come to me automatically.”

Swanson said far from being a burden, it would be a pleasure to watch her sisters grow up – adding she cares nothing for the grant she would receive as a foster parent.

“I don’t care about money,” she said. “I’d like to adopt them. They can keep the stipend.

“I don’t look at this as a responsibility. They are my family, and I can’t abandon my family.”